import org.omg.CORBA.INTERNAL;

import java.util.ArrayList;

public class Demo3 {
    public static void main(String[] args) {
        int[] arr = new int[]{1,1,2};
        // ArrayList<Integer> arrayList = new ArrayList<>();

        int sum = 0;
        for(int i = 0;i < arr.length;i++){
            sum ^= arr[i];
        }

        System.out.println(sum);
    }
}
